Showers are conventionally provided with a floor drain through which water is drained from the shower into the plumbing system for passage to waste. Such drains typically include a perforated or grid-like strainer through which liquid flows into the drain for flow to waste however the strainers which are employed have openings of such a size that solid materials particularly hair and skin still pass from the shower recess through the strainer and thus into the drain. This can cause blockages in the drain causing possible internal flooding. Alternatively the plumbing system can become blocked necessitating cleaning or unblocking by skilled persons such as plumbers. This can be expensive particularly if the blockages occur in locations where excavations are required to be carried out to gain access to the plumbing system where blockages have occurred. Similar problems can be encountered with drains which are used in baths, sinks, basins or simply in floors.